Inhibition of UV-induced ear skin swelling by systemic application of NF-κB decoy ODN. BALB/c mice received two intraperitoneal injections of NF-κB decoy ODN (open circles), scrambled ODNs (closed triangles), or PBS alone (closed circles) at 24 hours and 1 hour before irradiation. These animals were exposed to UV radiation and then examined for ear swelling responses at the indicated time points (a), surface density of epidermal Langerhans cells at 24 hours after irradiation (b), and CPD formation at 5 minutes after irradiation (c). Data shown in a are representative of three independent experiments, showing the mean ± SD (n = 10) of ear swelling responses (compared with ear thickness before irradiation). ^AStatistically significant differences (P < 0.05) compared with the UV plus PBS group. ^BStatistically significant differences (P < 0.01) compared with the UV plus PBS group. ^CStatistically significant differences compared with the UV plus scrambled ODN group (P < 0.05). ^DStatistically significant differences compared with the UV plus scrambled ODN group (P < 0.01). Data shown in b are the mean ± SD (n = 10) of numbers of IA⁺ epidermal cells/mm² in ear skin samples. Immunofluorescence pictures shown in c are representative staining profiles with anti-CPD mAb H3 or with an isotype-matched control IgG. ×400.